The Differences Between 3D Printing and CNC Machining

The most straightforward answer: 3D printing is an additive manufacturing technique, while CNC machining is a subtractive manufacturing technique.

Next, let’s compare 3D printing and CNC machining based on the following four points:

3D printing and CNC (Computer Numerical Control) machining are both advanced manufacturing processes, but they differ significantly in terms of how they create objects, their applications, and the materials they work with. Here are the key differences between 3D printing and CNC machining:

Working Principle:

3D Printing: 3D printing, also known as additive manufacturing, builds objects layer by layer from a digital 3D model. It deposits material, often in the form of filaments or resin, to create the final object. This means you can create complex geometries with ease.

CNC Machining: CNC machining, or subtractive manufacturing, removes material from a solid block or workpiece to shape the final object. It uses cutting tools, such as drills and mills, to subtract material from a stock material.

Materials:

3D Printing: 3D printing is versatile and can use a wide range of materials, including plastics, metals, ceramics, and even composites. The material options vary depending on the 3D printing technology used.

CNC Machining: CNC machining primarily works with solid materials like metals (e.g., aluminum, steel, titanium), plastics, wood, and some composites. The choice of materials is more extensive for CNC machining in terms of available options.

Speed and Production Volume:

3D Printing: 3D printing is generally slower than CNC machining, especially when producing large or complex objects. It is better suited for prototyping, custom parts, and low to medium production volumes.

CNC Machining: CNC machining is typically faster and more suitable for mass production due to its ability to remove material rapidly. It’s often used for high-precision and high-volume production.

Accuracy and Tolerance:

3D Printing: While 3D printing can achieve high accuracy, it might not be as precise as CNC machining when it comes to tight tolerances and fine details. The final product may require post-processing to improve dimensional accuracy.

CNC Machining: CNC machining offers exceptional precision and tight tolerances. It is known for its high level of accuracy, making it ideal for applications where precision is critical.

Complexity of Geometry:

3D Printing: 3D printing excels at creating complex, intricate, and organic shapes. It is particularly useful for producing parts with internal cavities or undercuts that are challenging for traditional machining methods.

CNC Machining: CNC machining is better suited for simpler geometries and parts that have flat surfaces or straight lines. It may struggle with intricate, highly complex designs.

Setup and Tooling:

3D Printing: 3D printers are relatively easy to set up, with minimal tool changes required. They are well-suited for rapid prototyping and design iterations.

CNC Machining: CNC machines require more setup time and tool changes. They are better suited for long production runs where the initial setup costs can be offset by higher production efficiency.

Post-Processing:

3D Printing: 3D printed parts often require post-processing steps like sanding, painting, or assembly to meet specific requirements or achieve a desired surface finish.

CNC Machining: CNC-machined parts usually require less post-processing, as they often have a high-quality surface finish directly from the machining process.

In summary, the choice between 3D printing and CNC machining depends on the specific requirements of a project. 3D printing is great for rapid prototyping, customization, and creating complex shapes, while CNC machining excels in precision, speed, and mass production of parts with simpler geometries.

At Fubon Precision, we have over 13 years of industry experience. Importantly, we have dealt with a wide range of various manufacturing methods such as CNC machining, 3D printing, sheet metal processing, and more to produce metal or plastic components according to the customers’ specifications while ensuring quality and on-time delivery. We are therefore well-poised to understand the various issues than plague the industry and how robust testing can help overcome these issues. To know more, please explore our PCB manufacturing services